Two more.questions regarding to that:
1) It was known how to generate a new address without a ptivate key back in 2009? If I'm right, this comes from a modern BIP (deterministic wallets)

I invented it in 2011:
https://bitcointalk.org/index.php?topic=19137.msg239768#msg239768 as a response to people reusing addresses because they didn't want to have private keys online. It was later standardized as BIP32.
2) I don't care about privacy, I prefer to have a working Donation address all the time rather than being 100% a ghost. :p
You may not currently care, and its your right to screw over your future self (which you may well be doing)-- but reuse also harms _other_ users in Bitcoin, who do care about privacy, and this degrades the fungibility of coins; since coins which are linked to this or that party are clearly different, and differently valuable than coins which are linked to other parties or are not linked.